Hi Dave
The attached patch now includes a fix for the regression you found. When the query tool is in edit mode, the user can copy rows and paste them. I've also removed the two lines from copy_data.js that you mentioned so that users can copy from the table even after they have copied once.
I have noticed that the "Paste Rows" button remains enabled even if only columns are copied. Although pressing this button won't do anything unless rows have been copied to the clipboard, this might prove confusing to users. I am going to look at disabling this button until rows are in the clipboard. I will let you know if I have anything for you by the end of today.
Best,
Matt